1. Field of Invention
The present invention relates to stereoscopic display means which enable the formation of at least a pair of images having parallax therebetween.
2. Description of Prior Art
It is known to produce an illusion of depth or of parallax by providing an observer with a pair of separate images taken from points of view a short distance apart and arranging for each image to be viewed from one eye only.
Stereoscopic display means have previously employed simple blinker like shields and/or binocular eyepieces together with paired photographs or display screens to achieve this object.
As an alternative to separate images, overlaid images have been displayed on a single screen. With "anaglyph" systems these images have differing colors and may be separated by suitably colored filters worn over the eyes. Analogous systems have employed polarising filters worn over the eyes.
In a further alternative, a pair of alternating images are displayed on a single screen and the eyes of an observer are alternately occluded in phase with the images, enabling image separation to be achieved.
Holograms and parallax panoramagrams are also known to provide an illusion of static three-dimensionality.
With the exception of holograms and panoramagrams, all of the above systems enable the stereoscopic display of moving images, but require the observer to wear some form of optical assembly such as blinkers, lenses, polarising filters or colored filters over the eyes. While holograms and panoramagrams do not require the use of such optical assemblies they are generally unsuitable for the display of moving images.